I'm using cmake to generate protobuf files like this:
file(GLOB PROTO_FILES
${PROJECT_SOURCE_DIR}/*.proto
)
PROTOBUF_GENERATE_CPP(PROTO_SRCS PROTO_HDRS ${PROTO_FILES})
My protoc is v3.14 so when I use proto3 version and optional fields, I need to set --experimental_allow_proto3_optional according to https://github.com/protocolbuffers/protobuf/blob/v3.12.0/docs/field_presence.md#protoc-invocation, how can I do it in cmake?
Related
My computer has multiple versions of the eigen library. I have an eigen3 in the /usr/include/ and another eigen3 in the /usr/local/. I use the set() command in cmakelists, but the compiler only uses the eigen library in the/usr/include directory. Here are my cmakelists.txt settings
`
cmake_minimum_required(VERSION 2.8.3)
project(cmake_test)
set(EIGEN3_DIR "/usr/local/eigen-3.3.9/share/eigen3/cmake/")
find_package(Eigen3)
include_directories(
# "/usr/local/eigen-3.3.9/include/eigen3/"
${PROJECT_SOURCE_DIR}/include
${EIGEN3_INCLUDE_DIR}
)
message("EIGEN3_INCLUDE_DIR =======" ${EIGEN3_DIR})
message("EIGEN3_INCLUDE_DIR =======" ${EIGEN3_INCLUDE_DIR})
add_executable(cmake_test src/main.cpp)
`
Does anyone know where I went wrong
I hope someone can tell me how cmake searches for header files, library files, and Search order of the find_ package() command
Basically, I want to have my structure like such:
MainRepo
+---app1
+---app2
+---common
+---some_lib1
+---some_lib2
+---protobuf
+---comms.proto
+---cs
+---Comms.pb.cs
+---cpp
+---comms.pb.cc
+---comms.pb.h
I want to be able to check out the repo and have a script that runs protoc for all the different languages for the apps that are in the repo. This is a mono repo containing an app for two different arm machines and an x64. I essentially are running protoc and it generates all the source files for c, js, cs, cpp, etc and puts them under protobuf in their own folders.
I want to have app1, for example, go find the c++ header and source and use them to build the app. At the moment, the example I have been hacking, uses cmake to generate the .cc and .h which makes it inconvenient for me as intellisense complains since those files dont exist when I'm writing.
Anyway, I've been hacking away at cmake all day. I always end up with cmake having a forward declaration error and cant compile my .cc and .h
PROJECT(test)
CMAKE_MINIMUM_REQUIRED (VERSION 2.6)
SET(CMAKE_CXX_FLAGS "-g -Wall -Werror -std=c++11")
ADD_EXECUTABLE(main main.cpp)
TARGET_LINK_LIBRARIES(main proto ${PROTOBUF_LIBRARY})
find_package(Protobuf REQUIRED)
set(PROTOBUF_IMPORT_DIRS "../proto")
set (msgs ${PROTOBUF_IMPORT_DIRS}/communications.proto)
PROTOBUF_GENERATE_CPP(PROTO_SRCS PROTO_HDRS ${msgs})
add_library(proto SHARED ${PROTO_SRCS})
target_link_libraries(proto ${PROTOBUF_LIBRARY})
Wondering if there are any suggestions. I dont want to have my protobuf stuff outside of my common folder and I also dont need protoc to generate those files either as I do that another way (although I could change that way). I just want to ensure that the language specific files are still available to view and not just generated during cmake and I cant view them.
My 2 cents,
Here this is what I did for google/or-tools
ref: https://github.com/google/or-tools
Protobuf Integration
I'm using Fetchcontent() (CMake >= 3.18 to have SOURCE_SUBDIR option IIRC), but I also need to patch it (e.g. to have CMP0077)
you can find the protobuf patch here: https://github.com/google/or-tools/blob/stable/patches/protobuf-v3.12.2.patch
cmake/dependencies/CMakeLists.txt
include(FetchContent)
set(BUILD_SHARED_LIBS OFF)
set(CMAKE_POSITION_INDEPENDENT_CODE ON)
set(BUILD_TESTING OFF)
message(CHECK_START "Fetching Protobuf")
list(APPEND CMAKE_MESSAGE_INDENT " ")
set(protobuf_BUILD_TESTS OFF)
set(protobuf_BUILD_EXPORT OFF)
set(protobuf_MSVC_STATIC_RUNTIME OFF)
# FetchContent_Declare(SOURCE_SUBDIR) was introduced in 3.18
FetchContent_Declare(
protobuf
GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
GIT_TAG "v3.12.2"
PATCH_COMMAND git apply "${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v3.12.2.patch"
SOURCE_SUBDIR cmake)
FetchContent_MakeAvailable(protobuf)
list(POP_BACK CMAKE_MESSAGE_INDENT)
message(CHECK_PASS "fetched")
ref: https://github.com/google/or-tools/blob/a0a56698ba8fd07b7f84aee4fc45d891a8cd9828/cmake/dependencies/CMakeLists.txt#L142-L168
note: for cmake < 3.18, I use ExternalProject + execute_process()
see: https://github.com/google/or-tools/blob/a0a56698ba8fd07b7f84aee4fc45d891a8cd9828/cmake/utils.cmake#L66-L137
Generate Protobuf files
Since we have integrated Protobuf, now we have access to protobuf::protoc.
To build proto file, simply adapt
# Get Protobuf include dirs
get_target_property(protobuf_dirs protobuf::libprotobuf INTERFACE_INCLUDE_DIRECTORIES)
foreach(dir IN LISTS protobuf_dirs)
if ("${dir}" MATCHES "BUILD_INTERFACE")
message(STATUS "Adding proto path: ${dir}")
list(APPEND PROTO_DIRS "--proto_path=${dir}")
endif()
endforeach()
# Generate Protobuf cpp sources
set(PROTO_HDRS)
set(PROTO_SRCS)
file(GLOB_RECURSE proto_files RELATIVE ${PROJECT_SOURCE_DIR}
"common/protobuf/*.proto"
)
foreach(PROTO_FILE IN LISTS proto_files)
#message(STATUS "protoc proto(cc): ${PROTO_FILE}")
get_filename_component(PROTO_DIR ${PROTO_FILE} DIRECTORY)
get_filename_component(PROTO_NAME ${PROTO_FILE} NAME_WE)
set(PROTO_HDR ${PROJECT_BINARY_DIR}/${PROTO_DIR}/${PROTO_NAME}.pb.h)
set(PROTO_SRC ${PROJECT_BINARY_DIR}/${PROTO_DIR}/${PROTO_NAME}.pb.cc)
#message(STATUS "protoc hdr: ${PROTO_HDR}")
#message(STATUS "protoc src: ${PROTO_SRC}")
add_custom_command(
OUTPUT ${PROTO_SRC} ${PROTO_HDR}
COMMAND protobuf::protoc
"--proto_path=${PROJECT_SOURCE_DIR}"
${PROTO_DIRS}
"--cpp_out=${PROJECT_BINARY_DIR}"
${PROTO_FILE}
DEPENDS ${PROTO_FILE} protobuf::protoc
COMMENT "Generate C++ protocol buffer for ${PROTO_FILE}"
VERBATIM)
list(APPEND PROTO_HDRS ${PROTO_HDR})
list(APPEND PROTO_SRCS ${PROTO_SRC})
endforeach()
ref: https://github.com/google/or-tools/blob/a0a56698ba8fd07b7f84aee4fc45d891a8cd9828/cmake/cpp.cmake#L234-L279
After you can use PROTO_HDR and PROTO_SRC e.g. add them to your target sources etc...
note: for .Net you can take a look at
https://github.com/google/or-tools/blob/a0a56698ba8fd07b7f84aee4fc45d891a8cd9828/cmake/dotnet.cmake#L30-L60
All in all, just adapt to your need, e.g. generate in source tree than binary dir etc. and you should be able to do whatever you want...
I am trying to link my local version of gflags (which is in ~/mylibs/gflags) while compiling google-test. In gtest's CMakeLists.txt, it's using find_package:
if (WITH_GFLAGS)
find_package (gflags 2.2.0)
if (gflags_FOUND)
set (HAVE_LIB_GFLAGS 1)
determine_gflags_namespace (gflags_NAMESPACE)
endif (gflags_FOUND)
endif (WITH_GFLAGS)
I don't want to modify the CMakeLists.txt file. Is there anyway to tell cmake to find the package in my folder ?
Thanks!
The gflags documentation describes specifying the location of a non-standard installation when using CMake:
The gflags_DIR variable must be set to the <prefix>/lib/cmake/gflags directory containing the gflags-config.cmake file
In your case, this might look like:
cmake -Dgflags_DIR=/home/blackball/mylibs/gflags/lib/cmake/gflags [...]
Since you are integrating gflags as subproject in a super cmake, you basically want find_package() to be a no-op if you have it in your "meta-project" source dir. This can be done by overloading the find_package() command.
Top CMakeLists.txt:
# Use find_package everywhere, no-op if it's a subproject
macro(find_package)
if(NOT TARGET ${ARGV0} AND NOT TARGET ${ARGV0}::${ARGV0})
_find_package(${ARGV})
else()
if(TARGET ${ARGV0})
get_target_property(TGT_VER ${ARGV0} VERSION)
set(TGT ${ARGV0})
else()
get_target_property(TGT_VER ${ARGV0}::${ARGV0} VERSION)
set(TGT ${ARGV0}::${ARGV0})
endif()
message(STATUS "Found ${ARGV0}: CMake Target ${TGT} (found version \"${TGT_VER}\")")
set(${ARGV0}_FOUND TRUE)
endif()
endmacro()
note: for gflags you may need to "force" gflags_NAMESPACE also since gflags it's a source not a binary (cf glog issue ToDo)
this is my current CMakeLists.txt file
cmake_minimum_required(VERSION 3.3)
set(CMAKE_C_FLAGS " -Wall -g ")
project( bmi )
file( GLOB SRCS *.cpp *.h )
add_executable( bmi ${SRCS})
This builds from my source directory, but I have to clean up all the extra files after. My question is how do I build this from a build directory if all my source files are in the same source directory?
thanks
If you really need to use file(GLOB …), this CMakeLists.txt should work :
cmake_minimum_required(VERSION 3.3)
project(bmi)
add_definitions("-Wall" "-g")
include_directories(${PROJECT_SOURCE_DIR})
file(GLOB SRC_FILES ${PROJECT_SOURCE_DIR}/*.cpp)
add_executable(bmi ${SRC_FILES})
In this case you have to launch cmake from your build directory every time you add or delete a source file :
cmake <your_source_dir> -G <your_build_generator>
As Phil reminds, CMake documentation doesn't recommend this use of GLOB. But there are some exceptions. You'll get more information on this post.
If you don't meet those exceptions, you'd rather list your source files than use GLOB :
set(SRC_FILES ${PROJECT_SOURCE_DIR}/main.cpp
${PROJECT_SOURCE_DIR}/bmi.cpp
… )
NB : if you have #include of your .h files in .cpp files, I don't see any reason to put them in add_executable, you just need to specify include directory with include_directories.
Cmake used to only update the list of source files if CMakeLists.txt was changed since the last cmake run or if cmake was used to configure the project again.
In cmake 3.11.0 recursive search and automatic re-configuration on adding or deleting source files was added. Since then you can use the following snippet:
if(${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.11.0")
file(GLOB_RECURSE SOURCE_FILES CONFIGURE_DEPENDS *.cpp *.h)
else()
file(GLOB SOURCE_FILES *.cpp *.h */*.h */*.cpp)
endif()
The file() command after the else() provides at least a bit of backwards compatibility: It still searches for source files in the current folder and its direct subfolders. But it doesn't automatically recognize if there are new files or old files have been deleted.
Note that VERSION_GREATER_EQUAL is only available in cmake >= 3.7
I have a custom target that is in fact an externally generated library that I want to integrate in my build.
add_custom_command(
OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/liblib2.a
COMMAND make -f ${CMAKE_CURRENT_SOURCE_DIR}/makefile liblib2.a)
add_custom_target(lib2
DEPENDS ${CMAKE_CURRENT_BINARY_DIR}/liblib2.a)
How can I tell cmake that this target is in fact a library, where it can be found and where are the headers ?
To be clear : I don't want the upper CMakeList using this library having to manually specify include folders and the library location folder It must be done automatically (from the target properties).
On a standard cmake library I would just have to add the INTERFACE_INCLUDE_DIRECTORIES property in the library CMakeLists to make cmake link my app with the relevant -I and -L gcc parameters :
set_target_properties(lib1
PROPERTIES
INTERFACE_INCLUDE_DIRECTORIES
${CMAKE_CURRENT_SOURCE_DIR})
But in the case of a custom target I don't know how to to it.
Any clue ?
Thanks for your help.
Thanks to zaufi it works!
For others who may be interested in embedded externally build target inside cmake here is what I did :
cmake_minimum_required(VERSION 2.8)
SET(LIB_FILE ${CMAKE_CURRENT_SOURCE_DIR}/bin/liblib2.a)
SET(LIB_HEADER_FOLDER ${CMAKE_CURRENT_SOURCE_DIR}/include)
# how to build the result of the library
add_custom_command(OUTPUT ${LIB_FILE}
COMMAND make
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
# create a target out of the library compilation result
add_custom_target(lib2_target DEPENDS ${LIB_FILE})
# create an library target out of the library compilation result
add_library(lib2 STATIC IMPORTED GLOBAL)
add_dependencies(lib2 lib2_target)
# specify where the library is and where to find the headers
set_target_properties(lib2
PROPERTIES
IMPORTED_LOCATION ${LIB_FILE}
INTERFACE_INCLUDE_DIRECTORIES ${LIB_HEADER_FOLDER})
Now in a CMakeLists.txt I can do somthing like
add_subdirectory(${ROOT_DIR}/lib1 bin/lib1)
add_subdirectory(${ROOT_DIR}/lib2 bin/lib2)
add_executable(app app.c )
target_link_libraries(app lib1 lib2)
No need to specify where the .a and the .h are.
You can use add_library() and tell that it actually imported. Then, using set_target_properties() you can set required INTERFACE_XXX properties for it. After that, you can use it as an ordinal target like every other built by your project.
Thank you for posting the solution. I have wrapped your snippet in a function:
function(add_external_library)
set(options)
set(oneValueArgs TARGET WORKING_DIRECTORY OUTPUT COMMENT)
set(multiValueArgs COMMAND INCLUDE_DIRS)
cmake_parse_arguments(ARGS "${options}" "${oneValueArgs}" ${multiValueArgs}" ${ARGN})
# Specify how to build the result of the library
add_custom_command(OUTPUT "${ARGS_OUTPUT}"
COMMAND ${ARGS_COMMAND}
WORKING_DIRECTORY "${ARGS_WORKING_DIRECTORY}"
COMMENT "${ARGS_COMMENT}")
# Create a target out of the library compilation result
add_custom_target(${ARGS_TARGET}_target DEPENDS ${ARGS_OUTPUT})
# Create an library target out of the library compilation result
add_library(${ARGS_TARGET} STATIC IMPORTED GLOBAL)
add_dependencies(${ARGS_TARGET} ${ARGS_TARGET}_target)
# Specify where the library is and where to find the headers
set_target_properties(${ARGS_TARGET}
PROPERTIES
IMPORTED_LOCATION "${ARGS_OUTPUT}"
INTERFACE_INCLUDE_DIRECTORIES "${ARGS_INCLUDE_DIRS}")
endfunction()
# Example
add_external_library(TARGET YourLib
COMMAND /bin/bash compile_your_lib.sh
WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
OUTPUT "output/yourlib.a"
INCLUDE_DIRS "include/a" "include/b"
COMMENT "Building YourLib")
add_executable(YourExe)
target_link_libraries(YourExe YourLib)